VATA: polyvinyl alcohol- and tannic acid-based nontoxic underwater adhesive and its applications

Abstract

Tannic acid, a plant-derived substance, has recently received significant attention from researchers due to its various interactions with various substances such as hydrogen bonds, metal ion coordination, hydrophobic interactions, and covalent bonds. In this dissertation, we developed the green adhesives with tannic acid and polyvinyl alcohol via their hydrogen bonding interactions and studied widely its formation mechanism and its applications. First, we introduced the noble study on the underwater adhesive prepared by the above material. This adhesive showed the adhesive tensile strength over 70 kPa and stable underwater adhesive properties and demonstrated the reversible adhesion property to various adherends. We confirmed its environmentally non-toxicities for living creatures via evaluation with invertebrate nematode (Caenorhabditis elegans) and vertebrate (goldfish). Second, we demonstrated the its potential for wood adhesive from adhesion test with various substrates (e.g., metal, plastics, glass, and wood) in a dry environment. Third, we fabricated its nano-fiber web via electrospinning method and showed its potential for hemostatic material via mouse liver bleeding test. Last, we developed new phenol-amine superglue with adhesive shear strength over 6 MPa inspired by insect sclerotization process.